DP on 1A seats opening up.
I was "gardening" my reservations and then found that the 1A seats of my flights (on A321 & A333) were surprisingly unblocked six months ahead. Curiously, only 1A was released and the rest of first row are still blocked. I was able to select 1A using the check-in trick. One of them still shows as blocked on NH website (my ticket is NH award), but it shows as available on EF and can be selected on OZ website.
I did a quick EF search for several dates in January 2020 and found 1A's of OZ102 (ICN-NRT) are all released. I don't know what's behind it but it is certainly good news for 1A lovers!